Fix for Bug #1909738: Strangeness with hierarchical searches

Because it is useful I decided to continue to permit hierarchy for saved searches even though behavior will be a bit strange.

The following behaviors exist and will not be changed.
- Renames will not rename all items in the the hierarchy.
- Intermediate nodes that aren't 'real' searches will not offer the rename option.
- Drag & drop is disabled.

In addition I changed the behavior of "Add search" in "Manage saved searches". It used to act like a rename if the target name already exists, throwing away the old search expression. It now refuses.

src/calibre/gui2/dialogs/saved_search_editor.py

@@ -153,20 +153,13 @@ class SavedSearchEditor(Dialog):
             self.slist.addItem(name)
 
     def add_search(self):
-        d = AddSavedSearch(parent=self, commit_changes=False)
+        d = AddSavedSearch(parent=self, commit_changes=False, validate=self.validate_add)
         if d.exec_() != QDialog.DialogCode.Accepted:
             return
         name, expression = d.accepted_data
-        nmap = {icu_lower(n):n for n in self.searches}
-        if icu_lower(name) in nmap:
-            q = nmap[icu_lower(name)]
-            del self.searches[q]
-            self.select_search(q)
-            self.slist.takeItem(self.slist.currentRow())
         self.searches[name] = expression
-        self.slist.insertItem(0, name)
-        self.slist.setCurrentRow(0)
-        self.current_index_changed(self.slist.currentItem())
+        self.populate_search_list()
+        self.select_search(name)
 
     def del_search(self):
         n = self.current_search_name
@@ -184,7 +177,9 @@ class SavedSearchEditor(Dialog):
         n = self.current_search_name
         if not n:
             return
-        d = AddSavedSearch(parent=self, commit_changes=False, label=_('Edit the name and/or expression below.'), validate=self.validate_edit)
+        d = AddSavedSearch(parent=self, commit_changes=False,
+                           label=_('Edit the name and/or expression below.'),
+                           validate=self.validate_edit)
         d.setWindowTitle(_('Edit saved search'))
         d.sname.setText(n)
         d.search.setText(self.searches[n])
@@ -196,10 +191,17 @@ class SavedSearchEditor(Dialog):
         self.searches[name] = expression
         self.current_index_changed(self.slist.currentItem())
 
+    def duplicate_msg(self, name):
+            return _('A saved search with the name {} already exists. Choose another name').format(name)
+
     def validate_edit(self, name, expression):
         q = self.current_search_name
         if icu_lower(name) in {icu_lower(n) for n in self.searches if n != q}:
-            return _('A saved search with the name {} already exists. Choose another name').format(name)
+            return self.duplicate_msg(name)
+
+    def validate_add(self, name, expression):
+        if icu_lower(name) in {icu_lower(n) for n in self.searches}:
+            return self.duplicate_msg(name)
 
     def select_search(self, name):
         items = self.slist.findItems(name, Qt.MatchFlag.MatchFixedString | Qt.MatchFlag.MatchCaseSensitive)

src/calibre/gui2/tag_browser/model.py

@@ -1372,10 +1372,12 @@ class TagsModel(QAbstractItemModel):  # {{{
         if index.isValid():
             node = self.data(index, Qt.ItemDataRole.UserRole)
             if node.type == TagTreeItem.TAG:
-                if node.tag.is_editable or node.tag.is_hierarchical:
+                tag = node.tag
+                category = tag.category
+                if (tag.is_editable or tag.is_hierarchical) and category != 'search':
                     ans |= Qt.ItemFlag.ItemIsDragEnabled
-                fm = self.db.metadata_for_field(node.tag.category)
-                if node.tag.category in \
+                fm = self.db.metadata_for_field(category)
+                if category in \
                     ('tags', 'series', 'authors', 'rating', 'publisher', 'languages') or \
                     (fm['is_custom'] and
                         fm['datatype'] in ['text', 'rating', 'series', 'enumeration']):

src/calibre/gui2/tag_browser/view.py

@@ -685,7 +685,9 @@ class TagsView(QTreeView):  # {{{
                 if tag:
                     # If the user right-clicked on an editable item, then offer
                     # the possibility of renaming that item.
-                    if fm['datatype'] != 'composite' and (tag.is_editable or tag.is_hierarchical):
+                    if (fm['datatype'] != 'composite' and
+                            (tag.is_editable or tag.is_hierarchical) and
+                            key != 'search'):
                         # Add the 'rename' items to both interior and leaf nodes
                         if fm['datatype'] != 'enumeration':
                             if self.model().get_in_vl():